Silk screen printing machine



July 16, 1940. E. E. PERRY Er AL 2,207,818

SILK SCREEN PRINTING MACHINE July 16, 1940. E. E. PERRY Er AL SILKSCREEN PRINTING MACHINE 3 Sheets-Sheet 2 Filed June 9, 1939 miv N\ a., M@/M wA///// mi@ f4 Nw WMM hmm July 16, 1940. E. E. PERRY Er AL l2,207,818

SILK SCREEN PRINTING MACHINE Filed June 9, 1939 3 Sheets-Sheet 5 ffzz.a. f1.9. y

Patented July 16, 1940 I PATENT OF F ICE'.r

SILK SCREEN PRINTING MACHINE Ernest E. Perry and FrankA. Cameron,Worcester, Mass.; said Cameron assigner to :saidv -lipplimmm June 9,1939, serial No. 278,370

Claims.

This invention relates to a silk screen printing machine, and moreparticularly to devices for the spreading of paint, lacquer, rubber, orany material capable of -being spread.

'I'he principal objects of the invention include: providing a machine`for spreading asubstance over a certain area, the device beingeasily,adjustable to spread the substance over any predetermined area up tothe capacity of the ma- 1|)y chine; providing a pivotedspringheld`.recipro cable spreader or squeegee, the length of its pathbeing variable according to the size of work` to be spread; means forrestricting the tilt of the squeegee to the desired angle; means for 15lifting the squeegeefrom the screen at the ends of its path, up over theresidue of the substance being spread and then down to the screen againbehind the substance,l to return the latter while spreading on thereturn stroke; a hinged squeegee and stencil carrier mounting all theoperative parts of the machine, including a power source, the hingebeing entirely at one side of the work area and automatically adjustableto easily accommodate various sizes of stencil frames without manualattention, and a power operated, automatically reversible means totravel the ysqueegee a desired distance within the limits of themachine.

Further objects are the provision of an improved stencil machine whichis superior in point of simplicity and inexpensiveness, with a widerrange of usefulness and variation of the working area. l

Other objects and advantages of the invention $5 will appearhereinafter.

Reference is lto be had'to the accompanying drawings, in which f Fig. 1is a plan view of the entire machine:

Fig. 2 is a detail view of the transmission reversing rackand pinion,looking in the direction of the arrow 2 in Fig. 1;-

Fig. 3 is a side elevation of a part of the device, looklng in thedirection of the arrow 3 in u Fig. 1:

Fig. 4 is an end view, partly in section, on the line 4-4 of Fig. 3,some parts being broken away;

Fig. 5 is a perspective view oi' the adjustable 50 cam used to lift thesqueegee carrier;

Fig. 6 is a perspective view of the cam v to limit the tilt of thesqueegee;

Fig. 7 is an end elevation showing the adjustv able hinge. looking inthe direction of the arrow u Hung. Lpartsbeingbrokenforciaritn Fig. 8-is a fragmentary view of the stencil frame' and the material to beprinted; and

Figs. 9, 10, 11 and 12 are diagrammatic illustrations of the tilting andlifting operation of the squeegee. 5

The frame I of the machine is rectangular and may be of wood or metal orany desired material and supported on legs 2 at appropriate locations.-At each end of one long side of the frame there is attached by anyappropriate'means a 10 U-shaped angle iron 3, having the legs thereofvextending away from the frame, as shown in Fig. 7. The legs of eachangle iron are provided with vertically aligned holes to slidinglyaccommodate the pins 4, and each pin 4 is provided 15 with a series ofholes 5 for the reception of a stop pin 6, the latter being insertablein any hole to vertically position the pin 4 downwardly with respect tothe frame I. Adjacent the top of each pin 4 there is journaled atransverse rock m shaft 1, supporting the frame 8 for swinging movement.The swinging frame 8 is rectangular and comprises U-shaped bars 9, III,bolted or riveted together, as shown in Fig. 1, spaced side `bars I-Iattached at their ends within the U-shaped bar 9, one bar II lclosingthe U and the other bar II being spaced therefrom and located on theside of the shaft 1 away from the bar II). Attached to the legs of theU-shaped vbar 9V are odset members I2 which locate the frame 8 withrespect to the pins 4 and restrain the frame from endwise movement. `Thestencil frame I3 depends from, and isdetachably secured to, the bars II,by the connection I3', as shown in Fig. 4. u

A spring I4 is attached at one end to the frame 8 on the opposite sideof the rock shaft I from the stencil frame and the spring is attached atits other end to some convenient xed point, as the licor or leg 2. Thisspring normally holds the stencil frame and associated parts in elevatedposition. the frame being swung down to operative position by the footof the operator stepping o'n a treadle I5, whichis connected to theframe 8 on the side of the rock shaft 'I opposite to the spring I4, by alink I6.

Both ends of the spreader carrier are the same and one end has beenshown in detail, as in Fig. 4.

'I'he side bars `I I are grcoved on their inside 50 surfaces so that thegrooves face each other and the bars Il are provided with laterallyextending feet I'I yon which are slidingly supported blocks I8. Theblocks I8 are attached to the ends oi' the right angled'legs I'II of abar 20, spaces I9' 55 being provided between the ends of the legs |8 andthe feet I1. The blocks I8 are guided by the grooves in the bars II ontheir sliding movement, but, if desired, these blocks may be replaced byrollers or other bearings.

Adjacent the ends of the bar 20 there are provided borings for thereception of bolts 2|. On the lower ends of these bolts there areprovided bored blocks 22 for the reception of pivot pins 23 attached tothe ends of the squeegee carrier 24. The upper ends of the bolts 2|extend through appropriate holes in a bridge member 25, and wing nuts 26are screwed onto these bolt ends to support the bolts on the bridgemember and thereby support the squeegee carrier. A compression spring 21is located between the blocks 22 and the bar 20 to normally hold thesqueegee 28 against the stencil 29, bearing in mind that the bar 20 isrestrained against vertical movement by the attached blocks I8 in thegrooves in the bars II, while the bolts 2| are slidable in the bores inthe bar 20.

The squeegee 28 may be made of soft rubber or any other materialdesired, and is compressed between two slide plates 28 that are screwedinto the carrier 24. By this means a larger or smaller squeegee may besecured to the carrier.

The ends of the bridge member 25 are bent over, as shown in Fig. 4, andare provided with pins 30 supporting wheels 3| for rotary motion.

'I'he wheels 3| run along on the top of the rails enable easy sliding ofthe carrier 24 in a vertical direction, while in contact with saidinterior sides.

On the tops of the rails there are located vseveral cam elements 34,longitudinally adjustable on the rails I I and detachably securedthereto by means of connections 35. lThe wheels 3| on the bridge member25 ride on the rails and up cam surfaces 36 on the adjustable elements34, at each end of the stroke of the squeegee carrier. In order to allowthe bridge 25 to rise under influence of the cams, while the bar 20remains at a constant level, slots 31 are provided in' the outer facesof the leg members I9, and the wheel journals 30 ride up and down inthese slots, while maintaining a constant lateral relation of the wheels3 I, bridge 25 and bar 20. i

From the foregoing description it will be clea that as the squeegeecarrier is reciprocated on rails the springs 21 maintain thesqueegeepressed against the stencil and the dragof the latter on the squeegeecarrier pivots it to the position shown in Fig. 9 when the carrier istraveled to the left, and to the position of Fig. 12 when returning tothe right. One leg of the octagon cam 33 limits the degree of tilt ofthe squeegee, as clearly shown in these figures. As the carrier 24approaches the end of its stroke in either direction, the wheels 3| rideup on the cam sur` faces 36, thus forcing the bridge 25, and with it,the bolts 2|, upwardly. Asthe bolts are connected to the carrier 24, thelatter is also forced up against the action of springs 21, and due tothe inclination of the octagon surfaces, the carrier 24 is slid upwardlyinto vertical-position, the

squeegee leaving the stencil. and thus thevdrag of the latter ontheformer disappears. A slight further travel of the bar 20 andassociated parts in the same direction carries the squeegee somewhatbeyond the hea'ped up paint or other spreading material indicated at 38,the wheels 8| now riding on the horizontal part 36' of the cam 34.

Upon reversal of the travel of the carrier, the wheels 3| ride down thecam surfaces 36, the squeegee contacting the stencil which sets up adrag, and the squeegee is tilted in the Vopposite direction,-beinglimited in such tilt by the other leg of the octagon shaped cam 33.Thus, it is seen that the squeegee is traveled to spread the paint, orthe like; automatically lifted over the heaped up paint,vand alsoautomatically brought down,'tilted in the oppositedirection againcontacting and spreading the paint, etc. in the reverse direction,without attention from the operator, so far as the squeegee isconcerned.

The squeegee carrier is traveled by means of power, which is entirelylocated onl and supported by the swinging frame 8. A platform 48 ismounted in any desired manner on the bars 9, I0, as indicated in Fig. 1,and a motor 4| and a conventional reversing transmission 42 aresupported on the platform. I'he motor and transmission are -connected bythe usual pulleys and belt 43, and the output end of the transmissiontively connected to spaced chains 48 through adjacent leg I8 of the bar2|) by any desired connection 52, and the bottom runsof the chainsAtravel below the legs I9 in the space I9'.

The transmission 42 is provided with a reversing operator consisting ofthe pinion 53, and

a rack 54. When the rack 54 is moved to either right or left from itscentral position, the transmission is thrown into neutral and the chains48 stop, but when the rack is moved back to the central position by, forinstance, la leftward motion of the rack 54, the power is again engagedand the carrier moves to the left. If the carrier is at the left end ofthe machine, as shown in Fig. 1, and the transmission is in neutral, arightward pull on the rack will engage the power and the carrier willtravel to the right. 'I'he rack may be operated in its sliding movementby the lever 55, pivoted to the frame 8 at 56, and connected at 51through a lost motion connection to the rod 58 which is secured to therack by a set screw. In order to automatically throw the y thoughtnecessary to show them in the present' CaSe.

In the operation of the machine, the card ory other material to beprinted is placed on the frame the screen 29 is secured by any con-2,207,818 venient means to'the underside of the stencil frame Il, asshown in Fig. 8, and the latter is then secured to the rails II. Theoperator then steps'on the treadle I5, bringing the stencil and itsframe down ,on the material to be'printed,

and the paint, etc. is placed in position on the top of the stencil. Theoperator then manipulates the lever as above explained to start thesqueegee carrier along its path of travel which is horizontal, and dueto the cam elements 3l, the squeegee will rise over or jump the paint,or the like, near the end of the travel, assume a vertical position, andbe ready'to start back at any time desired, to reverse the spreadingoperation. In case a small size card is to be printed, the cams 34 andstop pins 59 are adjusted on their respective supports to the desiredposition corresponding to the size of the card and the squeegee will betraveled only over the desired length, thus saving time and paint, etc.It is therefore clear that this device will accommodate all sizes ofmaterial up to the capacity of the stencil frame easily andeconomically. 'Ihe springs 21 maintain the squeegee against the stencilin such a manner that the paint, etc. can only go in front of or underthe squeegee.

The adjustable hinge at, l and 'I is provided so that any size ofstencil frame or other device may be used. That is, ifa larger memberthan that shown at I3 in the drawings is to be used, the sliding pins lwill automatically compensate for the consequent increased space betweenthe frames 8 and I. Thus, practically any size of frame I3 can be usedwithout manual adjustment of the frame 8. A further advantage ofi` theswinging frame is that all the work, and the stencil and its frame, maybe placed in the machine from one side only, thus simplifying theoperation.- i

Having thus described'our invention and the advantages thereof, we donot wish to be limited to the details herein disclosed, otherwise thanas set forth in the claims, but what we claim is:

l. In a device of the character described, means for spreading aprinting substance on a surf/ace, means for traveling the spreadingmeans over the surface, resilient means normally holding said spreadingmeans in contact with-said surface, cam means for raising the spreadingmeans from the surface at the end of its travel, and means to stop thetraveling means at the point where the spreading means is in raisedposition, said rising means and said stopping means being adjustablealong the path of travel of said spreading means, whereby the latter maybe stopped and raised at any desirable point.

2. In a device of the class described, a printing substance spreader, acarrier therefor pivotally mounted in a traveling frame, means to limitthe pivoting of the carrier, a surface over which the spreader carriertravels in contact therewith, the spreader carrier being tilted in thedirection of travel by the friction created between the spreader and thesurface, means to raise the spreader and the surface, means to raise andlower the carrier at a predetermined point, and

means yieldingly placing the carrier in vertical position when raised,whereby it is reversely tilted by contact with said surface upon beinglowered and reversely traveled.

4. In a device of the class described, a spreader, means pivotallymounting said spreader, means to travel said mounting means with thespreader in contact with a surface, by which the spreader is tilted,means to yieldingly press the spreader against the surface, means tolift the spreader against the pressing means at a predetermined point,and means to place said spreader in a generallyv vertical position whenlifted.

5. In a deviceof the class described, a spreader, means pivotallymounting said spreader, means to travel said mounting means with thespreader in contact vwith a surface, whereby the spreader is tilted,means to limit the tilt, means pressing the spreader downwardly, meansto lift the spreader against the pressing means at a predeterminedpoint, means to position the spreader in vertical position upon thelifting thereof, said surface tilting the spreader reversely` upon areverse travel of the latter.

6. In a device of the class described, a spreader, means pivotallymounting said spreader on a horizontal axis intermediate its side edges,means to travel the mounting means horizontally, with one longitudinaledge of the spreader in contact with a surface, means at either side ofthe other longitudinal edge of the spreader to retain the spreader invertical position when stationary, andlin tilted position underinfluence of the friction of the surface when traveling.

7. In a device of the class described, a sup--l port, a horizontal rockshaft located at one side of the support, and journaled in a verticallyslidable support, a frame mounted on the rock shaft to be pivotedthereon, whereby the vertical position of the frame may be varied, astencil frame detachably secured to the underside of the pivoted frameto be clamped between the latter and the first named support, atraveling printing substance spreader, and means to travel the samemounted on the pivoted frame to spread a substance on the stencil, thespreader and the means to travel it being on opposite sides of the rockshaft.

8. In a device of the class described, a support, a horizontal rockshaft located at one side of the support, and journaled in a verticallyslidable support, a frame mounted on the rock shaft to be pivotedthereon, whereby the vertical position of the frame may be varied, astencil frame detachably secured to the underside of the pivoted frameto be clamped between the latter and the first named support, atraveling printing substance spreader, means to travel the same mountedon the pivoted frame to spread a substance on the stencil, the spreaderand the means to travel it being on opposite sides of the rock shaft,means to retain the pivoted frame with the stencil frame and spreadernormally in raised position, and means to depress the same.

9. In a device of the class described, a reciprocable frame supporting apaint spreader, power-operated means to reciprocate said frame,adjustable stop means in the path of the frame to be engaged thereby atany desired point in the path of travel of the frame, the stop meansbeing operatively connected to a. power interdicting device, whereby thereciprocating means is stopped upon engagement of the frame withthestop, manually operat'able' means associated with the connection betweenthe stop and the power mterdicting device, to reverse the operation ofthe power means, and adjustable cam means in the path of said spreaderset to raise the same upon said engagement of the frame and the stop.

10. In a device of -the class described, a traveling carriage having abridge-like element restricted to rectilinear movement, a memberoverlying said bridge: and capable of motion at an angle to the path ofsaid-rectilinear movement, a movable support associated with said memberand said bridge and having means to prevent mo ement of the same in onedirection with respect to said member, a resilient element tending tourge said support in said direction,` and a spreader attached to saidsupport.

11. In a devce of the class described, a traveling carriage having abridge-like element restricted to rectilinear movement, a memberoverlying said bridge and capable of motion at an kangle to the path ofsaid rectilinear movement, a movable support associated with said memberand said bridge and having means to prevent movement of the same in onedirection with respect to said member, a resilient element tending tourge said support in said direction, a spreader attached to saidsupport, and means in the path of said member to move the sameagainstthe action of the resilient element, with respect to said bridge,thus also moving said spreader.

12. In a device of the class described, vthe combination of a travelingcarriage having a transverse, support, a member above said support andsame upwardly against said resilient action,thus

raising the spreader.

13. In a device of the class described, the combination of a travelingcarriage having a transverse support, a m\ mber above said support andmounted for vert cal movement with' respect thereto, an elementAdepending from said member and resiliently"urged downwardly, and a'spreader attached to said element; with a'. cam means in the path ofsaid member, adapted to urge the same upwardly against said resilientaction, thus raising the spreader, said cam means being adjustable toany desired point in the path of the member.

14. In a device of the class described, a carriage, means to reciprocatesaid carriage, a member connected to said carriage and mounted formovement with respect thereto, an element slidsaid carriage against theaction of said resilient means, and cooperating guide means on saidcarriage and said member to restrict the latter to a movement at anangle to the path of reciprocation of the carriage.

15. In a device of the class described, a spreader, means pivotallymounting said spreader, means to travel said mounting frame, resilientmeans urging said spreader with respect to saidv mounting means,positive means to urge'said spreader in the opposite direction at apredetermined point in the travel of said mounting means, and cam meansto place said spreader in desired relation to said mounting means uponaction of said positive means, said cam means comprising a generallyU-shaped element having slanting surfaces on the inner sides of itslegs, between which a portion of saidspreader is located.

ERNEST E. PERRY. FRANK A; CAMERON.

